Galena Summit & Eastern Mtns

Avalanche problems

• 

  Persistent Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  2–3

  A variety of weak layers exist in the upper 3' of the snowpack (observation). They appear to be most problematic on middle and upper elevation sunny slopes where they exist as a crust+facet combination. These layers also exist on shadier aspects where an obvious crust may not be present and where we're occasionally finding surface hoar. 

  The exact location, makeup, and sensitivity of these layers vary and are difficult to pin down. The complexity and spatial variability of this problem make slope scale stability assessment a highly uncertain task. The safest bet is to assume one or more of these layers exist and are capable of producing a large avalanche. 

  These layers are slowly healing. Slopes steeper than about 35 degrees, and/or those with recent wind loading will take the longest to stabilize. Therefore, avoiding steep, wind-drifted terrain is an effective way to reduce your odds of triggering a large avalanche. 

  ADDITIONAL DISCUSSION: While triggering slides on faceted snow deep in the snowpack is unlikely, it can't be ruled out in steep, rocky, wind-affected alpine terrain. Slopes like these have variable snow depths, and thinner snowpack areas allow our weight to more easily impact deeply buried weak layers.

  

• 

  Wind Slabs

  N

  NE

  E

  SE

  S

  SW

  W

  NW

  • Alpine
  • Treeline
  • Below treeline

  Likelihood

  Possible

  Size

  1–1.5

  Yesterday, skiers near Baker Ck found small, sensitive drifts in middle-elevation terrain. These slabs will be thicker and more abundant as you climb into windier, alpine terrain. Look for evidence of fresh windblown snow such as drifts, pillows, and new cornice growth. Slabs commonly form just downwind of ridgelines or on the sides of cross-loaded gullies. While I'd expect these slabs to be relatively small, they are likely to be sensitive to your weight. 

  Cracking, or collapsing of the snowpack are clear signs that you've found unstable snow. Given the increased chances of triggering both a wind slab and a large persistent slab avalanche on wind-loaded slopes, the prudent move is to avoid obviously wind-loaded avalanche terrain.